属于这两个集合的第一个数字：
三,7,31,43,61,73,83,421,643,743,761,863,941,953,971,983,7541,7621,7643,8431,8543,8741,8753,8761,9421,9521,9631,9721,9743,76543,87541,87631,87643,97651,98543,98641,98731,764321,986543,987541,987631,8764321,8765321,9754321,97654321,98764321.